It is well known to fabricate a building under mass production assembly line conditions, thereafter to transport the prefabricated building unit to its building site and to lift the prefabricating building unit into place on a prepared foundation at the site.
Examples of assembly line techniques for prefabricating building units such as house structure are to be seen in U.S. Pat. Nos. 3,805,365, 3,820,216 and 3,994,060.
Specialized units for transporting the building unit through the assembly line during fabrication are to be seen, for example, in U.S. Pat. Nos. 3,962,773 and 4,450,617.
An example of transporting modular home sections from the fabricating assembly line to the placement site, by means of flatbed trucks, is to be seen in U.S. Pat. No. 4,512,120.
Finally, lifting devices for use with cranes to lift the prefabricated unit and place it in its final place are to be seen, for example in U.S. Pat. Nos. 3,800,493 and 4,501,098.
Such systems suffer from the disadvantage that the assembly line is located remote from the building site. These previous arrangements have also suffered drawbacks in that the building unit during fabrication has required a great deal of handling on the assembly line and the systems for moving the units being fabricated though the assembly line have been complex, or suffered from handling drawbacks when moving the prefabricated structure on to a truck to transport it to the building site. Also the devices for lifting the prefabricated building units into position have been complex and somewhat difficult to use.